Distribution of beta-globin haplotypes among the tribes of southern Gujarat, India Aastha Aggarwal a , Priyanka Khurana a , Siuli Mitra a , Bhavesh Raicha b , K.N. Saraswathy a , Yazdi M. Italia b , Gautam K. Kshatriya a, ⁎ a Department of Anthropology, University of Delhi, Delhi 110007, India b Valsad Raktdan Kendra, R.N.C. Free Eye Hospital Complex, Kacheri Road, Valsad, Gujarat 396001, India abstract article info Article history: Accepted 27 February 2013 Available online 14 March 2013 Keywords: Indo-European Heterozygosity Linkage disequilibrium Genetic affinity The present study was carried out in Indo-European speaking tribal population groups of southern Gujarat (India) to elucidate the allelic and haplotypic content of β-globin system in individuals with HbAA genotypes. 6 neutral restriction sites of the β-globin system were analysed and various statistical parameters were estimated to draw meaningful interpretations. All the 6 sites were found to be polymorphic and most were in Hardy–Weinberg Equilibrium in the studied group. Haplotypes were constructed using two different combinations of the 6 restriction sites analysed. Analysis of the 5 sites revealed a set of three predominant haplotypes, ‘+----’, ‘-++-+’ and ‘-+-++’; and haplotypes ‘+--’, ‘++-’ and ‘+++’ were found to be the most frequent when the 3 sites were used to construct the haplotypes. Haplotypic heterozygosity levels (>83%) observed in the present study group were comparable to those observed in African and Afro-American populations and greater than other world populations. All the ancestral haplotypes, +-----, -++-+, -+-++ and ----+ were found in the study group. The distribution pattern of various haplo- types was consistent with the global pattern. The paucity of comparable data from other Indian populations restricted one from making interpretations about the study group's relationships with other Indian populations but the results were indicative of older population histories or experience of gene flow by the study group and their affinities with populations of southern India. © 2013 Elsevier B.V. All rights reserved. 1. Introduction β-Globin gene cluster is located on chromosome 11 in humans (11p15.5; Grzeschik and Kazazian, 1985) and consists of developmental- ly regulated genes involved in haemoglobin synthesis. The cluster is com- prised 5 expressed genes and one pseudogene. It also consists of a 9.1 kb long recombination “hotspot” 5′ to the β-globin gene (Antonarakis et al., 1982). Mutations in β-globin gene located in this region are known to cause several diseases and hence the gene is under selection pressure. Numerous neutral polymorphic restriction sites have been looked into and investigated for constructing haplotypes in this region of the genome. These haplotypes have been explored in several populations both with clinical and evolutionary perspectives in mind. Many studies have focussed on searching for clinical relationship of these haplotypes with sickle cell mutation or thalassaemias (Adorno et al., 2004; Kulozik et al., 1987; Majumder et al., 1999; Mukherjee et al., 2004; Niranjan et al., 1999; Powars and Hiti, 1993) and hence have limited implications for evolutionary studies. Other studies with anthropological orientation have made use of these haplotypes to capture human variation and to study genetic relationships of populations across the globe (Chan et al., 1986; Chen et al., 1990; Latini et al., 2003; Long et al., 1990; Luz et al., 2010; Magaña et al., 2010; Ramsay and Jenkins, 1987; Wainscoat et al., 1986). Molecular diversity and gene frequencies at a neutral locus would be affected by selection at a linked locus (Fay and Wu, 2000). Keeping this in mind, haplotype analysis was carried out only for β A chromosomes so that comparison could be made between populations in which selection is operating (because of presence of Hb*S) and populations in which it is not. Different investigations have made use of variable number of polymorphic sequence variants located in non-coding regions to con- struct the haplotypes. Because of the presence of recombination “hotspot” in the region the haplotypes can be divided into 5′ and 3′ sub-haplotypes corresponding to the regions 5′ and 3′ to the “hotspot”. The 5′ haplotypes have been widely used to investigate evolutionary re- lationships between human populations (Chan et al., 1986; Chen et al., 1990; Latini et al., 2003; Long et al., 1990; Luz et al., 2010; Magaña et al., 2010; Ramsay and Jenkins, 1987; Wainscoat et al., 1986) but this is not true for 3′ haplotypes. Such studies have mainly been carried out in populations of African, European or Oceanic origins or in admixed pop- ulation groups from Europe and America. But only few studies have reported such data on Indian groups, and these few studies have made use of only three restriction sites (Saraswathy et al., 2008, 2009; Gene 521 (2013) 287–292 Abbreviations: LD, linkage disequilibrium; GIS, Gini–Simpson index; DNA, deoxyribonucleic acid. ⁎ Corresponding author. Tel.: +91 9899915374; fax: +91 11 27666614. E-mail address: g26_51@yahoo.co.in (G.K. Kshatriya). 0378-1119/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.gene.2013.02.039 Contents lists available at SciVerse ScienceDirect Gene journal homepage: www.elsevier.com/locate/gene